Automated welding device for the buildup of material

ABSTRACT

An apparatus, for providing a welding bead on a surface to be welded, comprises an arm supporting a welding torch in which the welding torch facilitates welding on a desired surface. A spindle supports the arm and the welding torch and at least a portion of an exterior surface of the spindle carries a thread. A motor supplies rotational drive to the spindle and causing rotation of the spindle and the arm which supports the welding torch. A framework supports a clutch, the drive and at least a portion of the spindle, and the clutch is supported by the framework so as to be engageable with the thread carried by the exterior surface of the spindle. The clutch has an engaged position, in which the clutch engages with the thread carried by the exterior surface of the spindle to cause axial movement of the spindle, relative to the framework, upon rotation of the spindle via the drive to facilitate the welding torch depositing a spiral weld on the surface to be welded, and a disengaged position in which the clutch is sufficiently spaced from the thread carried by the exterior surface of the spindle so that the spindle can be moved axially relative to the framework.

BACKGROUND OF THE INVENTION

[0001] A wide variety of machinery exists in working conditionsthroughout the world and is exposed to abrasive and stressfulconditions. Large work loads, open and corrosive conditions and time allwork to wear-out bearing surfaces and require replacement and or repair.For large bearing surfaces, there is often a need to buildup material inthe inner surface of the inner surface of the bearing bore. Variousattempts have been made to provide automated machinery for depositingwelding beads in a uniform manner on the inner bores of bearingjournals.

[0002] For instance, U.S. Pat. No. 4,527,039 to Fuwesi teaches anapparatus and method for restoring the surfaces blind or throughsurfaces of metallic workpieces. Fuwesi teaches a method by which tool,including welding torches, can be connected to a rotating spindle. Theeffective radii of rotational movement of the welding torch in Fuwesi isfixed by combination of the length of the welding attachment itself, andthe spindle mechanism. Fuwesi does not disclsoe a manually adjustableaxial positioning mechanism.

[0003] U.S. Pat. No. 4,687,899 issued to Acheson teaches a an apparatusfor restoring the inner surfaces of bores in metallic workpieces thathas an adjustment means that relies on fixed pieces connected with agear mechanism for adjusting the effective radii of the welding torch.This mechansim will be either quite large or will have a small range ofadjustable radii. As another embodiment Acheson's apparatus, there is aprovided a two part mechanism for adjusting the radius of the weldingarm, a radial arm and an arm parallel to the axis of rotation of theaxis of the apparatus. It is clear that Acheson requires severalembodiments of the device in order to provide a wide range of radii.

[0004] U.S. Pat. No. 5,298,710 issued to Acheson also teaches anapparatus for building up material in a large bore of a metallicworkpiece. In developing the Acheson technology of prvious patents,includingn U.S. Pat. Nos. 4,873,419; 4,892,990; and 4,925,769; Achesonhas releid upon additional setups to provide a greater radii range andhas developed and claimed a specific method of sweeping the inner borethat sweeps about 360 degreees and then makes a step, effectively equalto the welding bead.

[0005] The typical trend has been to make devices that are capable ofdoing many operations, including building up bore surfaces and littleattention has been paid to providing equipment that is responsive to theneeds and conditions imposed by day to day operations. However, none ofthe prior art references are specifically configured to be easy to setup in the field, their primary working condition. Each of the systems iscomplicated and requires careful attention to setup parameters in orderto insure proper operation. The present invention is designed to alloweasy setup and use through means of easy adjustment of the apparatusthrough manual adjustment of the significant positioning parameters,simple linear controls to adjust process parameters of the buildupprocess, and, relatively small size.

[0006] It is an object of the invention to provide a device foruniformly building upper the inner surface of a bore, that is easy tosetup.

[0007] It is a farther object of the invention to provide an apparatusthat provides a very uniform buidup of material on the inner surface ofa bore.

[0008] It is also an object of the invention to provide an apparatus forthe buildup of material that easy to position and reposition or tochange direction of the movement of the apparatus along an axis.

[0009] It is also an object of the invention to provide an apparatusthat will create a spiral buildup mechanism, simple manual axialadjustment, and simple manual radial adjustment

[0010] Furthermore, it is an object of the invention to provide linearadjustment of buildup rate and sweep rate of the device in operation.

SUMMARY OF THE INVENTION

[0011] The present invention relates to an automated welding device usedto build up material on the inner surface of a bore so that the bore canbe restored to original working order. The apparatus is characterized inhaving various improvements over the state of the art devicesspecifically including a welding extension arm that has a first andsecond hollow arm joined with a swivel bearing that allows radialadjustment of a welding torch nozzle that extends from the second hollowarm; a unitary mechanical mechanism that coordinates the rotation of thewelding arm and the axial movement of the welding torch; a manuallyreleasable mechanism for adjusting the initial radial position of thewelding arm and readjustment of the same; and a conductive path thatprovides current flow in external portion of the device is limited tothe first and second hollow arm of the welding torch arm. Furthermore,the welding core assembly which carries the welding

DESCRIPTION OF THE FIGURES

[0012]FIG. 1 A three-quarters view of one embodiment of the presentinvention.

[0013]FIG. 2 A view of the lower axial displacement means of oneembodiment of the present invention.

[0014]FIG. 3 A view of the rotation control apparatus placement means ofone embodiment of the present invention.

[0015]FIG. 4 A view of the swivel control placement means and lowerportion of the welding material supply mechanism of the presentinvention.

[0016]FIG. 5 A cross-sectional view of the conduit assembly of thepresent invention.

[0017]FIG. 6 A vertical cross-sectional view of the hollow spindleassembly.

[0018]FIG. 7 shows a horizontal cross-section showing the spindle, andits rotation drive mechanism.

[0019]FIG. 8 shows a horizontal cross-section of the spindle and theclutch mechanism.

DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention an apparatus for providing a uniformwelding bead on the interior surface of a circular bore comprising: afirst hollow arm rotateable along a radial axis; a swivel bearing meansattached at a first point to the first hollow aim aligned on said radialaxis; and a second hollow arm attached to a second point of said swivelbearing means so as to be disposed away from said radial axis. Thissimple mechanism allows an operator in the field to adjust the mechanismto work in bores of varying radii. As can be seen in FIG. 1 the operatorwill align the axis of the first hollow arm 1 along the desired axis ofthe bore 10 and placing the nozzle 11 of the welding torch at thestarting point of the bore where material is to be built up. Adjustmentof the effective radii of the apparatus is achieved by swinging thesecond hollow arm 12 at the swivel bearing means 13 and positioning thenozzle of the welding torch 11 in working proximity of the bore surface.

[0021] The apparatus can be conveniently aligned with the bore by fixingthe clamping means 9 to a fixed surface and then adjusting theadjustable support bracket means 7 including adjusting the effectivelength of the mounting rod 8. Once fixed, the radial position of thewelding arm can be finely adjusted in the invention by a clutchmechanism, 22 in FIG. 3, that releases the welding carrier mechanism tobe freely moved to its desired position.

[0022] The clutch mechanism engages a threaded guide 4 that controls theaxial movement of the welding mechanism as the welding mechanism isrotated about its axis. Clearly, the rate of axial movement depends uponthe size of the thread on said threaded guide. Those skilled in the artwould find it straightforward to adjust the thread size for particularwelding operations. In the practice of the present invention the screwsrange from six to ten turns per inch, although preferably there areseven to eight. The invention may be practiced with screw dimensionsoutside this range as conditions might require.

[0023] As shown in FIG. 3 the housing 3 for the control unit surroundsthe spindle 21 a which extends through the control unit and carries thewelding material carrier mechanism. The control box has a clutch controlmechanism 22 attached to the clutch means, a rotational speed control 24attached to the control mechanism in the controller and a directionalcontroller 23 for moving the spindle forward or in reverse. The spindle23 a has a screw mechanism portion 20 b, and a portion at the oppositeside of the controller 20 c. There may be disposed at opposing ends ofthe spindle, a first clamping or positioning means 21 and a second clamp25 that also provides an indication of the position of the spindle.

[0024] The welding materials supply mechanism comprises a welding wireguide liner, an welding current path; and a welding gas conduit. FIG. 2shows the second arm 12 attached to the swivel bearing means 13 and thehollow first arm 1. A welding wire guide passes through the first arm,the swivel bearing means and the second arm and through a gas diffuser17 to a welding tip 18 and through the welding nozzle 19. The weldingcurrent runs through the wall of the first hollow arm, the swivelbearing means and the second hollow arm to the nozzle and tip. Gas issupplied through the first and second hollow tubes to the gas diffuser.

[0025] The first and second hollow arms are attached to the swivel hinge14 and a locking coupler 16 and are tightened in the desired positionwith locking nut 15. The upper arm runs though an extension tube intothe spindle of the apparatus, and is electrically insulated from theextension. tube

[0026]FIG. 4 shows the rotating portion of the welding core includingthe female electrical conductor 26, the hollow first arm wall 27, theflexible, wire conductor 28 and a locking nut 29 for attaching the armto the swivel bearing. This mechanism is carried within an extensiontube that runs through the spindle and to the swivel bearing means. Itis as the swivel bearing that welding potential runs through an exteriorportion of the apparatus, through the second hollow arm, the gasdiffuser and the tip of the welding torch.

[0027]FIG. 5 shows wire/power/gas conduit 5 with the wire guide liner 28attached to an adapter 32, a retainer ring 33 and the stationary currenttransfer connector (or male electrical connector) 34. It is important tonote that the current path in the present invention does not follow anexterior surface until it reaches the swivel bearing. The welding coreis carried in the spindle by an extension tube and the welding core isisolated from the extension tube by a plurality of o-rings 35.

[0028] In operation the apparatus of the present invention may be easilysetup, by first positioning the apparatus along the axis of the bore tobe rebuilt. This is accomplished by any number of methods. In one methodthe workpiece is fixed to a stationary object and the axis of theapparatus is aligned with the bore. This may be accomplished initiallyby sight and then adjusted when the apparatus is setup by adjusting theball joint anchor and he adjustable brackets. In many instances, theworkpiece will include more than one bore that needs to be refurbished.In many instances, such as in construction equipment, there will be atleas two bores that share a common axis. Alignment can be accomplishedby use of a rod with two opposing conical slideable attachments (a firstand second slideable conical attachments). The first cone is placed intothe first bore and the second cone is slid along the rod into the secondbore. A portion of the rod passes through the hollow spindle of theapparatus to allow fixturing of the apparatus to both bore axis.

[0029] After aligning the apparatus axially, the bore tip can be placedin the desired starting point by releasing the clutch of the apparatus(if the alignment rod was used it is removed and the welding core isslid into the apparatus, fit into the spindle and tightened intoposition). Upon placement, the welding core is re-engaged to the spindleby engaging the clutch.

[0030] The effective radius of the welding core is then adjusted byadjusting the nozzle of the welding torch to an optimal working distanceby swiveling the torch (the nozzle and the second hollow arm) of thewelding core through the swivel bearing means.

[0031] In operation, after the apparatus has been aligned along the axisof the bore, the welding torch has been adjusted for radius and initialstarting position by engaging the spindle at the correct axial positionand swinging the welding torch into working position by pivoting throughthe swivel bearing, the apparatus starts its operation. The spindle isrotated about its i axis and welding materials (welding current, weldingwire and welding gas) are supplied through the welding core to thewelding torch which then deposits a strip of metal to the inner boresurface as torch rotates around the inner circumference of the bore.Because the spindles axial position is a function of the clutchmechanism's contact with the threaded screw portion of the spindle, asthe spindle rotates its axial position changes. The screw portionsthread density determined the number of spirals per inch that the torchmoves, a spiral pattern of material is built up on the inner boresurface. When the desired portion of the bore is built up, the processis shut off. Clearly, the bore can also be built up with several layersby repeating the above process.

[0032] The removable welding core of the present invention, shown inFIGS. 4 and 5 is comprised of a first hollow arm rotateable along aradial axis; a swivel bearing means attached at a first point to thefirst hollow arm aligned on said radial axis; and a second hollow armattached to a second point of said swivel bearing means so as to bedisposed away from said radial axis where said first hollow arm attachesto a a rotateable electrical connector comprising a first female portionand a second male portion wherein the electrical contact is formedbetween an outer radial surface of said male portion and an innersurface of said female portion and the male portion connects to flexibleconduit that carries the welding wire and welding wire conduit, aconduit to transport the welding gas mixture and an electricalconductor. This welding core is insertable and removable from thecontrol and rotation controller; this controller comprises a hollowspindle; a drive mechanism for rotating the hollow spindle; andfixturing means for holding the welding core. Specifically thecontroller further comprises a manual clutch mechanism for allowingslideable adjustment along the axis of rotation and a screw mechanismthat coordinates the axial and radial movement of the spindle. Thespindle may be connected to the welding core through electricallyinsulated means in order to isolate the spindle from electrical currentand minimize the exposure of welding current to the lower portion of thewelding core.

[0033]FIG. 6 shows the spindle assembly which is comprised of thespindle tube 40, a keyway 41 disposed on the exterior surface of thespindle tube, a key 42 disposed in said key, a pulley 43 fixed to saidkey and positioning means. The drive v-belt 51 runs around the pulley 43and the motor pulley 52.

[0034]FIG. 7 shows a cross-section of the motor-pulley, v-belt andspindle drive pulley. The figure also shows the spindle, with the keyand keyway with the spindle bushing disposed between spindle and thespindle drive pulley.

[0035]FIG. 8a and 8 b shows a horizontal cross-section of the controlbox and illustrates the working of the clutch mechanism. AS can be seenthe clutch control knob 61, is connected to a clutch pivot point 62through an arm 63 that is tensioned through a tensioning means pressinga nut section 64 against the threaded portion of the spindle 65. Asshown in the figures the tensioning means is a simple spring. In FIG. 8athe nut section is engaged into the treads and in FIG. 8b the clutch armis pivoted disengaging the nut section out of the threads.

[0036] Thus, the apparatus of the present invention allows a veryuniform volume of material to be deposited on the inner surface of acylindrical bore by employing the device with a state of the art Migwelding apparatus. The apparatus need not limited to any particular formof welding and those skilled in the art of welding would be able toadapt the specific embodiments disclosed herein to other weldingtechniques.

What is claimed is:
 1. An apparatus for providing a uniform welding beadon the interior surface of a circular bore comprising: a first hollowarm rotatable along a radial axis; a swivel bearing means attached at afirst point to the first hollow arm aligned on said radial axis; and asecond hollow arm attached to a second point of said swivel bearingmeans so as to be disposed away from said radial axis.
 2. An adjustablewelding apparatus comprising a welding tip positioning means; a meansfor rotating said welding tip placement means about an axis; and a meansfor coordinating the radial movement of the welding placement means bysaid rotating means with an axial movement component to form a spiralmovement wherein said means for coordinating said axial and said radialand axial movement is provided by a attaching the welding tippositioning means to a threaded screw guide and running said threadedscrew guide through a fixed point so that rotating the welding tippositioning means provides a spiral movement.
 3. An automated weldingapparatus comprising a radial adjustable welding arm; a means formanually setting the axial position of said welding arm.
 4. An automatedwelding apparatus comprising; A rotatable electrical connectorcomprising a first female portion and a second male portion wherein theelectrical contact is formed between an outer radial surface of saidmale portion and an inner surface of said female portion.